Apparatus for felting non-woven webs

ABSTRACT

FELTING APPARATUS FOR A NON-WOVEN WEB HAVING A BED PLATE OVER WHICH THE WEB IS FED AND TWO BANKS OF NEEDLES TO PENETRATE THE WEB FOR FELTING THE FIBERS. AN UPPER PLATE WITH A FLARED ENTRANCE GUIDES THE WEB IN THE FELTING STATION FOR REDUCING THE WEB BULK AS IT ENTERS. BOTH, STRIPPER AND BED PLATE HAVE ALIGNED HOLES TO PASS THE NEEDLES OF THE MAIN BAR IN THEIR PENETRATING STROKE, AND A SECONDARY NEEDLE BAR IN THE FLARED ENTRANCE SECTION, WHICH DOES NOT PENETRATE THE BED PLATE.

Sept. 20, 1971 H, BARTH 3,605,223

APPARATUS FOR FELTING NON-WOVEN WEBS Filed NOV. 26, 1969 FIG. I

I57 k I II INVENTOR v HERMANN BARTH .4 BY MML ATTORNEY United States Patent 3,605,223 APPARATUS FOR FELTING N ON-WOVEN WEBS Hermann Barth, Eberbach (Neckar), Germany, assignor to Richard Dilo, Eherbach (Neckar), Germany Filed Nov. 26, 1969, Ser. No. 880,090 Int. Cl. D04h 18/00 US. Cl. 28-4R 4 Claims ABSTRACT OF THE DISCLOSURE Felting apparatus for a non-woven web having a bed plate over which the web is fed and two banks of needles to penetrate the web for felting the fibers. An upper plate with a flared entrance guides the web in the felting station for reducing the web bulk as it enters. Both, stripper and bed plate have aligned holes to pass the needles of the main bar in their penetrating stroke, and a secondary needle bar in the flared entrance section, which does not penetrate the bed plate.

This invention relates to apparatus for felting nonwoven fiber mats or webs and more particularly to apparatus of the type having banks of needles constructed and arranged to penetrate the loose fiber web and to force some of the fibers through the mass for interfelting the fibers.

An object is to provide an apparatus of the above type which particularly adapted for use with webs of synthetic fibers which are difficult to bring between stripper and bed plate because of their bulky characteristics and because of their inherent springiness and resilience.

Another object is to provide such apparatus having means for compacting and interfelting a comparatively loose and very bulky web.

Another object is to provide apparatus of the above type having novel and improved features of construction.

Various other objects and advantages will be apparent as the nature of the invention is more fully disclosed.

In apparatus of the above type the unfelted web in a bulky state is fed by a conveyor system and feed rolls over a bed plate in a needle punching station wherein a bank of needles is reciprocated through the web. The needles extend through the web and through aligned holes in the bed plate to force some of the fibers through the mass so as to cause interfelting thereof.

In using apparatus of this type it has been found that the web, because of its bulk and springiness is difficult to compress and enter between the bed and stripper plates without distortion. The extent of distortion depends upon the looseness of the fiber mass and the characteristics of the fibers which are being treated. In any event it interferes with the formation of a compact interfelted web.

In accordance with the present invention this springback is prevented by providing an upper stripper plate which guides the web along the bed plate. This stripper plate has holes for the free passage of the needles and is shaped at its entrance end to form a flared zone for receiving the fiber mass from the feed rolls of the machine, and to provide room for an auxiliary needle bar, to felt the same.

The nature of the invention will be better understood from the following description, taken in connection with the accompanying drawing wherein a specific embodiment has been set forth for purposes of illustration.

In the drawing:

FIG. 1 is a longitudinal vertical section through felting apparatus embodying the invention;

3,605,223 Patented Sept. 20, 1971 ice FIG. 2 is a transverse, vertical section taken on the line 2-2 of FIG. 1;

FIG. 3 is a longitudinal, vertical section similar to FIG. 1 but showing the needles in retracted position, and

FIG. 4 is a detail perspective view of the needles. Referring to the drawing more in detail the apparatus is shown as including a pair of conveyors 10 between which a web 11 of unfelted fibers is fed from a source, not shown. The web is fed from the conveyors 10 between a pair of feed rolls 12 by which the mass is compacted and fed to the felting station.

The felting station comprises a bed plate 14 on which the web 11 is supported as it advances, and an upper stripper plate 15 which guides the web 11 and holds the same in compacted state. The stripper plate 15 may be inclined to the base plate 14 in the direction of travel of the web so as to progressively compress the web as it is felted, and is formed with a flared entrance end 16 to assist in directing the web between the two plates, and to provide room for the needle bar 21A.

A plurality of rows of needles 20 are mounted in needle bars 21 and 21A carried by a plate 22 which is reciprocated vertically by suitable means, not shown, to cause the needles 20 to penetrate the web 11. The plates 14 and 15 are provided with holes 23 and 24 respectively which are aligned with the needles 20 for allowing the needles to pass therethrough in their penetrating stroke. The stripper plate 15 is mounted in fixed position by means of a suitable bracket, not shown and is preferably adjustably mounted on the bracket for accommodation to webs of different thicknesses.

The first two or three rows of needles at the flared entrance end of the stripper plate do not com letely penetrate the web and do not extend through the holes in the bed plate 14 below. These needles serve to remove the air from the web 11 and to compact the same. Certain of these needles may have smooth sides and may be formed with a blunt end 30 as shown in FIG. 4. These needles readily penetrate the web and cause some interfering of fibers. Others 'of the needles are formed with barbs 31 to assist in forcing the fibers through the mass so as to interfelt the same. The stripper plate 15 serves to strip the fibers from the needles and to prevent sprin-gback of the web when needles are retracted, so that the web is progressively compacted and interfelted as it advances through the felting station. The flared entrance section facilitates the entrance of the web into the zone between the bed plate and the stripper plate.

It is understood that certain of the needles in the auxiliary bar 21A may be passed through the web at a different angle if desired for assisting in randomly interfelting the web as it advances. This may be accomplished by altering the linear path of the web as it passes through the felting station or by arranging for the needles located inside the flared entrance section to be angularly mounted and reciprocated.

Needle felted webs normally weigh less than one kilogram per square meter. When using the method described herein, webs weighing two kilograms per square meter can be readily produced. Speed is increased, and blocking eliminated.

What is claimed is:

1. Apparatus for felting non-woven webs composed of randomly disposed fibers comprising a felting station including a bed plate on which said web is supported, means advancing said web along said bed plate, a plurality of rows of needles disposed at said felting station, means for reciprocating said needles in a path of penetrate said web for thereby interfelting said fibers, and a stripper plate disposed above said web at said felting station and having holes for the passage of said needles,

said stripper plate being adapted to strip the fibers from said needles and to hold the web compacted when the needles are withdrawn, said stripper plate having a flared entrance section, and a set of needles mounted to reciprocate through said flared entrance section and through the web thereunder.

2. Apparatus as set forth in claim 1 in which said first mentioned needles when advanced extend at least partially through said bed plate, and said last mentioned needles at the entrance end when advanced extend through said stripper plate and said web only.

3. Apparatus as set forth in claim 1 in which certain of said needles are formed with a blunt end and others are barbed to assist the felting step.

4. Apparatus as set forth in claim 1 in which certain of said needles in the flared section extend through said web in a path which is non parallel with respect to the path of others of said needles.

References Cited UNITED STATES PATENTS 3,112,549 12/1963 Smith 284 3,116,534 1/1964 OByrne 284 3,391,436 7/1968 Fehrer 28--4 LOUIS K. RIMRODT, Primary Examiner 

